Glycosylphosphatidylinositol-anchored proteins: Membrane organization and transport

Biochim Biophys Acta. 2016 Apr;1858(4):632-9. doi: 10.1016/j.bbamem.2015.12.018. Epub 2015 Dec 17.

Abstract

Glycosylphosphatidylinositol (GPI)-anchored proteins (GPI-APs) are a class of membrane proteins containing a soluble protein attached by a conserved glycolipid anchor to the external leaflet of the plasma membrane. In polarized epithelial cells, GPI-APs are predominantly sorted to the apical surface in the trans-Golgi network (TGN) by clustering in sphingolipid- and cholesterol-dependent microdomains (or rafts), which have been proposed to act as apical sorting platforms. Recent data indicate that the mechanisms of GPI-AP sorting, occurring in the Golgi, control both the membrane transport of GPI-APs and their specific activity at the apical surface of fully polarized epithelial cells. Here, we discuss the most recent findings and the factors regulating apical sorting of GPI-APs at the Golgi in polarized epithelial cells. We also underline the differences in the plasma membrane organization of GPI-APs between polarized and non-polarized cells supporting the existence of various mechanisms that control GPI-AP organization in different cell types.

Keywords: Apical sorting; Cholesterol-dependent domains; GPI-anchored proteins; Lipid–protein interaction; Nanoclusters; Oligomerization.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Cell Membrane / chemistry
  • Cell Polarity
  • Cholesterol / chemistry
  • Cholesterol / metabolism
  • Epithelial Cells
  • Glycosylphosphatidylinositols / chemistry*
  • Glycosylphosphatidylinositols / metabolism
  • Humans
  • Membrane Microdomains / chemistry*
  • Membrane Microdomains / metabolism
  • Membrane Proteins / chemistry*
  • Membrane Proteins / metabolism
  • Protein Transport*
  • trans-Golgi Network / chemistry
  • trans-Golgi Network / metabolism

Substances

  • Glycosylphosphatidylinositols
  • Membrane Proteins
  • Cholesterol